Spark-pltjg and process for making the same



C. H. BRASELTON. SPARK PLUG AND PROCESS FOR MAKING THE SAME.

APPLICATION FILED MAR. 5.1915- Patented July 29, 1919.

3 SHEETSSHEET 1 INVENTOR m a Q/WM' y f C. H BRASELTON.

SPARK PLUG AND PROCESS FOR MAKING THE'S'AME.

' APPLICATION FILED MAR. 5. 1915. 1,31 1,261.

w// /M/ 7///A1 Patent-ed July 29, 1919.

3 SHEETS-SHEET 2 llVI/ENTOR WITNESSES. P 5

C. H. BRASELTON.

SPARK PLUG AND PROCESS FOR MAKING THE SAME.

APPLICATION FILED MAR- 5.1915.

Patented July 29, 1919.

3 SHEETS-SHEET 3.

lll'llllll INVENTOH UNITED STATES PATENT OFFICE.

cnns'nm n. BimsEL'roN, or DAYTON, omo.

SPARK-PLUG; AND FOB. MAKING" THE SAME.

To all whom it may concern":

Be it known that I, CHESTER H. BRAsEL- TON, a citizen of the UnitedStates, residing at Dayton, in .the county of Montgomery and State ofOhio, have invented certain new and useful Improvements in Spark-Plugsand Processes for Making, ,the Same, of which I declare the following tobe a full,-

clear, and exact description.

. This invention relates to spark plugs and the processes for makingthe-same. The inventions herein disclosed are specifically applied tospark plugs but some are capable of a broader application.

The spark plugs in this application are based upon an entirely new ideain spark plugs and processes of making the same.

and process of making it, which in its broad- -est aspect is capable ofapplication to other articles other than spark plugs; a novel Beingbasic in this respect the disclosure in. this application extends toVarious points of advantage in the construction of spark plugs and inthe processes of manufacturingithem. These include a novel gasketconstruction process and construction in regard to secur-.

ing the central electrode of-a spark. plug in placein the insulator in agas tight'manner;

- a novel-construction and process as regards fastening a terminal capon the upper end A of the insulator in place on the same or in fact, ifdesired, eliminating the separate cap completely; a novel constructionand process in regard to mounting a second. electrode onthe insulator sothat when the insulator is assembled inplace in the shell an electricalconnection will exist between the second electrode on the insulator sothat when the insulator is assembled in place in the'shell an electricalconnection will exist between the second electrode and the enginecasing;

' a construction and process for providing an 'insulator with one ormore electrodes with a metallic shell provided'with threads for securingit into an engine cylinder; and a novel construction and rocess forpractically providing-.a brit'fie substance with durable threads.

The above obf'ects are accomplished;

loy'ment of an idea of fying the material and breaking up the liquidinto infinitesimal portions and deposit 'ing such. portions upon thesurface to be. coated by blowing theliquid material by a specificationof Letters Patent.

- spark plug.

of a ribbon.

PatentedJuly 29, 1919.

Application filed March 5-, 1915. serial No. 12,359.

blast of gas under pressure against the surface to be coated to which itadheres so that a film of the material of any desired thickness placedupon the material to be coated.

With the above and other incidental objects in view, my inventionconsists further in various details of processes and construe tions morefully hereinafter described and pointed out in the appended claims.

In the drawings which accompany and form part of this specificationFigure his a view pf one form of spark plug'made in accordance with thisinvention.

Fig. 2. 1s a view showing my novel method of making-this spark plug.

F g. 3. is aview of a. different form of. spark plug which may be madeby my process, a metal shell being sprayed upon an in v sulator ofanydesired shape, the'threads in theext'erior" of the lower end being entin the metal after it is sprayed'upon the insulat0r.. u I

Fig. 4. shows a. diflerent form of spark plug in which theinsulator isattached to a she1 1- through the medium ofsprayed mate ria Fig. 5. is avertical section through the pllig of Fig. 4. 1 v 1g. .6.v is a View ofthe insulators of Figs. 4 and 5. v 1 Fig. 7. is still another view inwhich the insulator isjatta'chedto the shell through the .medium'of'sprayed material; the. insulator being of a different-form.

Fig. 8.'is a View of a different form of Flg. 9.- 's a yertical sectionthrough the plug of Fig. 8. 1

- F1g.:l0. is a view of the insulatoruof Fig. 9, showing gasketmaterialsprayed upon the seating shoulder of the insulator andconducting material may in the form of a ribbon or completelysurrounding the insulator,

be sprayed uponthe lower end of the insulator. This View"; also s oyvsan electrode wire sprayed"fast: -.to';the lower end of the porcelain"-at' its two ends,one end. at least ducting material leading to thesprayed gasket. I.

Fig. 11 shows Ian elevationof the insu lator of Figpl0 at right angles,as it'would appear with the-condilcting material on the lower'end of theinsulator'being inthe form beingpreferably connected with the conductingribbon to form a spark gap at the side.

,Fig. 14. is a cross section of the lower end of the insulator below theshoulder, of a case in which the conducting ribbon completely surroundsthe insulator.

Fig. 15. shows the lower end of an insulato with a second electrode, inthe form of a-ring or band, sprayed thereon.

Fig. 16. shows amanner of attachi-n a fibrous gasket to the shoulder inthe inside of the spark plug shell.

Fig. 17. shows a similar form of fibrous gasket attached to theinsulator.

Fig. 18. shows a thread detail which may be used in connection withspark plug shells in which threads cut in harder metal are sprayed witha softer metal so as to obtain a better gas tight threaded connection.

My inventions are based upon the idea of spraying one materialwithanother by heating the material to be sprayed with -to liquefy it andthen blowing the same into the form of a spray and against the surfaceto be coated It is necessary that the substance to be covered be cleanand preferably to an extent porous. I find it very easy to spray cleanearthenware or-glass which has a rough surface, and very well unglazedporcelain ware such as iscommonly used in spark plug constructionforinsulators. The surfaces tobe sprayed must of coursebe free from oilor grease. Such materials as well as metals can be readily sprayed withmetal by heating the metal into the form .ofliquid drops andblowing-same in the form of a spray against the clean surface to besprayed. A coating thick as desired may be thus made on the materialbeing sprayed threadedpart, with any desired metal, such as copper orbrass, soas to form a metal 7 sheath of any vdesired thickness over theby continuing the process for the required length of time. In thisspraying operation the minute particles of materialwith which thesubstance is being-coated seem to pene-j trate into all the tiny poresof thejmaterial being coated and; to adhere to the dame permanently andvery firmly so'that there is no --air or gas passage between thesurface" sprayed upon and the layer of sprayed ma terial. @Thisoperation is not limited- 'ito spraygng non-metals with metals butenemeta may be sprayed" with another metal; or a metal may be sprayedwith a non-metal which may ,be reduced to a liquidform and blown uponthe material to be sprayed. Or

a non-metal may be sprayed with another n onsmetal. The spraying operation maybe confined to: small areas are surface to be sprayed bycoating or coveringthe-area's ex t posed that are not desired to'besprayed the that which is to be sprayed may be protected from thespray by wool to which sprayed. meta-l does not adhere owing probably tothe inability to completely free the wool 1 from oil or grease.- Inspraying or coating spark plug insulators on certain area onl I firstglaze the areas not to be coated, having J5 the areas to be coatedunglazed. Holding the insulator in the spray of material then willresult in the unglazed areas beingpermanently and 'endurably coatedwhile-the spraying material will not adhere to the glazed surfaces andis readily removed.

I make use of the just described process in various ways of advantagein'the designingand constructing of spark plugs for in- 'ternalcombustion engines so as toimprove their service and design, as well ascheapen their cost of manufacture In Fig. l, 1 is aninsul'ator adaptedforuse in spark plugs which may be made of the'usual porcelain or anyother desired insulating material. This is made with any-form ofexterior desired and with threads-2 cut in'the insulator at the lowerend. It'was not a very practical proposition to provide, before myinvention, insulators suitable for spark plug use with threads on theirexterior for screwing into a threaded opening in an engine cylinderbecause the t reads in the brittle insulator, while capable of being cutor molded, will not stand b'ut will be broken and chipped so as to ,beunserviceable. It was also not very practical heretofore to engage theinsulator directly with a wrench for screwing it in place owing to thebrittle 1 nature of the insulating material. I find it very practical,however, to do both of these by constructing the'insulator with any dcsired exterior and with threads, by spray- 1n lia le to be readilybroken including the surfaces to be protected. The contour of thethreads in the insulating material before very satisfactory results aresecured anda very cheap construction as well, by thisrocess. If desiredthe threaded part may e. sprayedwith a softer'metal such as coporcoating the surface of the insulator .per, the other part, which may beany harder'inetal in order to'provide a better gas tight connection atthe threads. In I spraying threaded or'ot'her areas where relativelyaccurate thickness should be pre ably have the spray being blown upomthe rotate, preferably with a certain deterserved throgighout theperiphery,'I prefersurface at 'a relatively constantspeed afid- I minedspeed by machinery, the threaded the spray in the manner In Fig. 2 themember to be sprayed so that an ,even coating will be placed upon thethreads or any rotating object throughout the periphery.

In Figs. 1 and 2 the metal sheath is indicated by the character 3, thisbeing in the exterior form of a non-circle atthe upper end to receive awrench for use in screwing theplug into place in the threaded'opening.

This sheath will take. the form of the insu1a-.

tor inside if its surfaces are fed equally to above described. operationof sprayingwnthe threaded insulator is shown. In tlns view 4 isa holdingblock for a rod 5 of copper or brass or in fact any material with whichthe insulator is to be sprayed. The lower end of the rod is adapted tobe heated so that the material will form in drops at the lower end, by atorch T, such as an oxy-hydrogen torch, adapted to give suflicient heatto melt the rod 5 at its lower end. As the drops are formed at the lowerend of rod 5 they are broken up into the form of sprays and blown intiny particles against the surface to be sprayed by means of a blast ofgas, such as nitrogen. or air, issuing from the nozzle '6 under pressurewith a speed depending upon the gas used and the material ,with whichthe object is to be coated. 7 When the spray hits the object to becoated it .isdriven into the the insulator so as toform a spark gap 8bevlously sprayed upon to which the tiny parpores thereof or the poresofv the layer pre ticlesstrongly adhere and in a way weld to.thefsilrface and to the adjacent particles in a firmbond. Continuingtheoperation'increases the thickness of the sheath sprayed. In Fig.2 I showan electrode- 7 fastened at its ends to the lower'end of the insulatorand electrically to the lower end of the sprayed sheath 3 by a sprayingoperation. This electrode passes acros'sthe lower end of tween itsintermediate portion-and the lower end of center electrode 9. I Thecenter elec- 1 trode 9 runslongitudinally through the insulatorandelectrically connects, through a.

terminal cap and stud l0,'and binding nut 11, to alwire leading to oneside of the battery. The other electrode 7 on the lower end of theinsulator, through the metallic sheath 3, electrically connects with theengine casing and the ground back to the ot-her'side of the batteryormagneto. The spark plugs in Figs. l'zand 2 are similar with theexception of the electrode arrangements on the lower end i'," regard a.)which Fig. 1 differs from I Fig-..

just described by the substitution of' a straight electrode wire 12forthe second electrode instead of the electrode terminal 7 ofFig. 2. Inthis Fig.1 the electrode 12 is of course merely a piece of wire attachedto'themetal sheath 3 of 1 by spraying.

In Fig. '3 I, show a different way of perma nently providing threads forinsulating. ma-j menting operation.

, the insulator.

the electrode 16 and the bottom teriaL-this being done by having theinsulat ing material unthreaded and provided with a sheath of metal, byspraying, after which threads may be cut in the sprayed sheath by anyusual thread cutting operation. In this form I preferably extend thesprayed sheath 13 around the lower endof the insulator at 14 at whichpoint it will form one spark terminal between which and the opposingend15 of a center electrodelfi a spark will pass when the plug is in use. 1

In this form of Fig. 3, I further illustrate the center electrode 16 asbeing permanently secured in the insulator through the medium of sprayedmaterial instead of the usual ce- Thus I have .shown a film'17 ofsprayed material connecting the surfaces of the electrode 16 and theadjacent surface of the insulator at the lower end of This permanentlyattaches the electrode 16 to the insulator and in away preventing anypossibility of leakage of compression from the engine through the insulator around the axial electrode 16. I have shown the upper end ofthis electrode 16 extending into a counterbored opening 17 in the lipperend of the insulator- I have also shown a coating of metal sprayed uponthe adjacent surfaces of the upper end of.

of the counterboredv opening. This further insures a gas tightconnection of the center electrode withthe insulator. I provide aterminal stud 19 with a recess 20 at its lower end adapted to fit o erthe upper end of the center. electrode 16 and the exterior of the lowerend of this stud 19 I preferably have noncircular to fit the preferrednon-circular 1nterior of thecounterbore 17. This construction serves toprevent rotation-of the terminal stud 19 when in place on the insulator.l fasten the terminal stud 1,9 firmly the upper end' of the insulatorand connectin place by spraying" a cap 21 of metal over This cap I makeof sufiicient thickness. as to Y firmly support and hold the terminalstud'19- in place. A nut 11 similar to the one in-Figs. 1 and 2 is ofcourse used in'connection with the terminal stud 19 to receive one endof the battery or magneto wire.

In Fig. 4 I show a spark plug of a little different design made up oftwo main pieces; an outer metallic shell 22 threaded at 23 forattachment into an engine cylinder; and an insulator These two parts maybe of any desired-designandl permanently connectthem. together byspraying their adja-- cent surfaces at one-point by a layer of spray25.which securelyfastens the two main pieces-together in a gas tightmanner. In thisform of Figs. 4, 5 and 6 I have shown" the insulatorcarrying both electrode wires which it mayor may not do, one,runningcompletely through the insulator and the other only part way terminatingat the sur face of the insulator to be sprayed upon in fastening theinsulator in the shell. In this form. I have shown the upper end of thelonger electrode inelectrical connection with a terminal cap 26 of theusual construction adapted for receiving connection with a battery ormagneto .wire in the usual manner This'termlnal cap arrangement may beof the usual type *or may be different and placed upon the u'pper end ofthe insulator by means of a spraying operation in a manner similar tothat I have illustrated and described in connection with Fig. 3. Inthese figures I have shownthe' lower end of the insulator connected withthe lower end of the shell by ring 27 of sprayed material and both aperipheral groove 31 in the insulator where the spray is to be appliedso as-to'form a stronger connection between the insulator and the shellas regards longitudinal displacement. In this figure, 32 is a secondelectrode running longitudinally through the insulator. I preferablyhavethis electrode of a larger diameter at Its upper end to fill acounterbore 3a in the insulator. The'extreme end of the electrode beingthreaded'to receive a nut 35, I fasten the electrode in I place and tothe. insulator by spraying a coating 36 of metal on the upper surface ofthe insulator and against the periphery of the largaportion of theelectrode.

' In Figs@ 9, 10, l1, l2, and 13 I show a different type of spark plug,generally of the design well known on the market in whlch an insulator37 is adapted to be secured in a shell 38 by means of 'a screw bushing39 screwing into threads in the inslde of the shell so as-to carry theinsulator down and bring its downwardly facing shoulder 40 against theupwardly facing shoulder 41 on the inside of the shell. "Usually agasket of separate construction is provided between these two contactingsurfaces to eliminate or reduce leakage of compression from the engine.I eliminate this separate gasket by spraying the shoulder on theinsulator with a soft metal such as copper so as to, in effect,

' make the soft copper gasket a part of the insulator. I leave thisseating shoulder on the "insulator, which is to'be sprayed with softcopper, u-nglazed so as'to better receiveiand hold the soft copper whichthus being perma'nently attached to the insulator still efiectivelyserves as a soft copper gasket between the two surfaces in thatthere is but one passage for gas fromthe cylinder between the trode tothe lower 'endof the insulator.

insulator and the shell, whereas there would be two if a separate gasketwere placed be tween the insulator and the shell seats, a passage on theupper surface of the gasket and a passage on the 'lowersurface. Thisconsiderably reduces the possibilityof leakage of compression at theseat between the informed of steel and I still further may improve thejoint at their seat by spraying on top of the shoulder in the shell andthe cop 'sulator'iand the shell. The shells are usually per on theinsulator expanding equally with" the heat, reduces considerably anydanger of coating of spray 43 around it where it pro-- trudes from thelower end of the insulator and a similar coating at around the upper endof the electrode and filling a counterbore +5 in the upper end of theinsulator. A

. terminal cap 46'is placed upon the upper end of the insulator thisbeing provided with the usual terminal stud and nut for receiving oneend of a battery or magneto wire. I permanently fasten the cap 46 inplace on the insulator by spraying a layer 47 of brass or copperon thesurfaces of the insulator and the metal cap where they meet so as topermanently connect the peripheries of the insulator and cap in anabsolutely gas tight manner. Of course the cap 46 may be dispensed withas a separate piece the terminal stud being a part of the centralelectrode or projecting into the insulator to touch the centralelectrode, thisterminal stud being fastened in place by a layer ofcopper or brass sprayed upon the upper end of the iny sulator and incontact with the periphery of the terminal stud as shown'in Fig. 11.

In order to provide the insulator with both sparking points so that ifthe invention isapplied to a quick detachable spark plug that theinsulator when removed will carry both points for cleaning andadjustment I ma fasten the second electrode on thelower en of theinsulator by placing the electrode 48 in place against -the lower end ofthe in-.'

'sulator and spraying'over its exposed surface and the adjacent surfaceof the insulator. This firmly secures the second .elecprefer to connectthis so attached second electrode to the sprayed shoulder by coating t eouter surface of the v insulator between the second electrode and the spraye d{shoulder' with a conductor. -This need not extend completelyaround the periphery ofthe insulator but may take the form of a-.ribbon49 shown most clearly in asket on the insulator outer periphery wallinside surface of the Fig. 11. Thisbein of sufficient current capacityto connect the secondelectrode with the sprayed copper gask which, whenthe insulator is in place, is in engagement with the shell which isgrounded through the engine to the other side of the battery or magneto.shown a section of the lower end of the insulator as it would appearifinstead of a ribbon 49 only, the conducting material was sprayed so asto cover the-whole lower surface of the insulator exterior. This wouldprevent any oil-soaking of the insulator from I passage of oil from theoutside of the insulator into the insulating material throughthe of theinsulator.

In Fig. 15, 50 is a band of sprayed metal on the lower end of theinsulator'and in this form I have, eliminated the electrical connectionbetween this second electrode and the sprayed gasket on theinsulator andpropose that this second electrode will make an electrical connectionwith the inside of the spark plug shell wall by jumping across the smallgap between theexterior of this electrode ring or band and the inside of'the shell. The main spark occurs between the bent end of the centralelectrode and the lower surface of this second electrode ring. yinterposing this second sparking gap between the second electrode andthe inside of the shell it is claimed by many that a sharper and betterigniting spark results at the main sparking point.

In Fig. 16, I show a manner of attaching an asbestos or othernon-metallic gasket to the shoulder on the inside of the shell. This isaccomplished by merely placing'a ring 51 of asbestos or other packing inplace on the inside shoulder of the shell and covering the packing by acoating 52 of soft copper which extends to, at its edges, and connectswith, the shell. This form of gasket construction is very effective inthat none of the fibrous packing is exposed but is confined and keptcompletely surrounded with metal so that it cannot become oil soaked oreasily damaged in use. This construction provides a yielding gasketwhich,

in some ways and for some uses, is preferable to an entirely metalgasket such as of soft cop-per.

In Fig. 17, I show a similar form of gasket construction. with theexception that the fibrous gasket. is secured to and confined againstthe shoulder on the insulator by a spray or coating of soft copper orother de-.

sired metal. Of course similar provisions of gaskets may be made on boththe contacting seats of the insulator and the shell if desired. Theseforms of gasket constructions are of course not limited to spark plug,

use but are equally of value-elsewhere as regards their broader aspect,yet being particularly advantageous in spark plug use owing et on theinsulator,

In Fig. 14 I have be coated be clean an insulator the area effectiveshield from spark plug shell are coated with a soft copper, brass, orsimilar material, so as to for a more eflicient gas tight connectionbetween the threaded members.

While I'have described various details of processes and construction I-do not mean to confine my protection to the same as various changes mayoccur to those skilled in the art coming Within the principle of myinven tion. I have shown and described applications of my invention asapplied to spark plugs for internal combustion engines but I do not meanto limit my protection to this application wherever the inventions in abroader aspect are new For example, the details of gasket constructionand manufacture which I have herein'shown and described .and which areparticularly advantaeous and patentable in a spark plug sense, I Eelieveto be new in a broader sense and patentable in this broader aspect aswell. The same is true as regards the effective threading of aninsulating body which it has been impractical to thread before myinvention of protecting the threads by sprayed metal, and of thespraying of metal upon an insulator or other brittle substances andcutting the threads thereafter.

In the above description wherever I have spoken or referred to sprayingportions of my plug it is necessary that the surfaces to for example bysand blasting or any other effective way of cleaning the surfaces.Furthermore, when spraying the'insulating material such as porcelain incarrying out my invention the surfaces to be sprayed should be leftunglazed. If these precautions are taken a durable effective bond willbe provided between the surface sprayed upon and the material with whichit is sprayed so that they will adhere to any ordinary usage and in sucha way as to prevent any passage of as or air between them at theirpoints of engagement. In order to prevent an area from being sprayedadjacent one desired to be sprayed if it be not desired to be sprayed ifglazed will not retain the sprayed material. Or interposing some othercollecting medium to shield'the area not to -be sprayed serves thesamepurpose. Covering an area not to be coated with wool is a very the sprayfor it, as stated above, will not retain the material sprayed upon it.Rapidly rotating an object to be sprayed on its periphery whilerexposedto the spray will insure a relatively even coating of the material overthe periphery of the objectl Wherever in the carrying out of thesecourse I may use steel orother metallic conducting material. FurthermoreI may .use a separate 'piece for the electrode and merely attach it byspraying to the insulator.

- I Obtain very desirable results from spraying the surface of the lowerend of the insulator, which projects into the engine for exposure to oilor heat with glass which gives me a very good 'oil resisting coating forthe insulator. I may as well coat any other portion of the insulatorwith glass as well where an electrical insulating materialv is desiredfor the protective covering. By doing this the insulator can be leftwholly unglazed and a coating of glass sprayed on for a glaze whereverdesired by the spraying operation.

'Particularly is this desirable for that portionof the lower end of theinsulator be-' tween the two electrodes such as the inside 'surfaces,coated with a she th of relatively of the reess' in the lower end of theinsulator.

' upon those portions of a body formed out of insulat ng material whichare adapted to contact with metallic surfaces,'by liquefying Havingdescribed my invention what I claim as new and desire to secure byLetters- 1. The process of making spark plugs comprising depositing ametallic sheath upon a body formed out ofinsulating' material byliquefying a-relatively soft metal,-

atomizing saidliquefied metal and projectmg said atomized metal uponsaid body by a blast of gas and forming screw threads in aportion ofsaid metallic'sheath.

2. The process of making spark plugs comprising forming screw threads ona. portion of a body formed out ofinsulating material, and depositing ametallic sheath upon said body, including the threaded portions thereof,by liquefying a relatively soft metal, atomizing said liquefied metaland projecting sa'id atomized metal upon said body by a blast of gas. V

3. The processof .makingspark plugs comprismg depositing a metallicsheath arelatively soft metal, atomizing said liquefied metal andprojecting said atomized metal upon said bodyby a blast of gas.

v 4. The process of threading amember of relatively brittle materialcomprising the depositin of a metallic sheath upon said member yliquefying a relatively soft rhetaL-atomizing said liquefied metal andprojecting'said atomized metal on the memher by a blast of gas andcutting-screw threads in said metallicsheath.

The process of threading a member of relatively brittlev materialcomprising the forming of screw threads on said member and thedepositing of a metallic sheathnpon said threaded portion by liquefyinga relatively soft metal, atomizing said liquefied metal andprojectingsaid atomized metal on the member by a blast of gas.

6. In a spark plug, the combination of a body of insulating material, asheath of relabody being provided with screw threads,

and a sheath of relatively soft metal deposited on said body, includingthe threaded portion, by liquefying said metal, atomizing saidliquefiedmetaland projecting said atomized metal on said body by a blastof gas.

8. In a spark plug, the combination of a body of insulating materialhaving portions,

which are adapted to contact with metallic soft metal by liquefying saidmetal, atomizthreads.

10. A threaded member comprisin a body of relatively brittle material,provi ed with screw threads, and a sheath of relatively soft'm'etaldeposited on the'threaded portion of said body by liquefying the metal,atomizing said liquefied metal and projecting said atomizedmetalon thebody by a blast of gas. I

11. The process of making spark plugs comprising the forming-of a bodyof insulating material'provided with a longitudinal passage, insert-inan electrode in said passage, and depositing a sealingmaterial againstthe surface of the electrode and the adjacent surface'of the-body byliquefying said material, atomizing said liquefied material andprojecting said atomized material on said surfaces by a blast of i a 12.The process of lnaklng spark plugs comprising the positioning of anelectrode in the desired relation to a body of insulating material anddepositing sealing material upon the adjacent surfaces of the a bodyand'the electrode by liquefying said materlal, atomizing said liquefiedmaterial a deposit on said body extending and'projecting said atomizedmaterial upon said surfaces by a blast of gas. j

, 13. In a spark plug, the combination of a body of insulating materialprovided with a longitudinal passage therein, an electrode disposed insaid passage and sealing material deposlted on the adjacent surfaces ofsaid body and said electrode by liquefying said material, atomizing saidliquefied material and pro ectlng said atomized materialupon said"surfaces by a blast of gas.

14. In a spark plug, the comb nation of a body of insulating materialand an electrode secured to said. body by sealing material deposited onthe adjacent surfaces of said body and said electrode by liquefying saidmaterial, atomizing said liquefied material and projectin said atomizedmaterial upon said surfaces Toy a blast of gas.

' 15. The process of making spark plugs comprising securing a centralelectrode in a body formed out of insulating material and provided witha shoulder, depositing arelatively soft metal on said-shoulder, depositing electrically conductive material on said body from a point adjacentthe end of said.

electrode to said shoulder by li'quefying said material, atomizing saidliquefied material and projecting said atomized material on saidbody bya blast of gas, and inserting said body in a metal shell provided withan internal seat with said said internal seat.

16. The process of making spark plugs comprising securing a centralelectrode in a body formed out of insulating material, depositingelectrically conductive material on said body at a point adjacent theend of said electrode by liquefying said material, atomizing saidliquefied material, and projecting said atomized material on said bodyby a blast of gas, and inserting said body in a metal shell With saidelectrically conductive material in proximity to said metal shell.

17. The process of making-spark plugs comprising securing a centralelectrode in a body of insulating material and depositing electricallyconductive material on said body at a point adjacent the end of saidelectrode by liquefying said material, atomizing said liquefied materialand projecting said atomized material on said body by a blast of gas.

18.v In a spark plug, the combination of a body of insulating materialprovided with a shoulder, a layer of metal on said shoulder, a centralelectrode secured in said body, a of electrically conductive materialfrom a point adjacent. the end of said electrode to said shoulder anddeposited thereon by liquefying said material, atomizing said liquefiedmaterial and projecting said atomized material on said body by a blastof gas, and a metallic shoulder engaging shell having an internal seatin which saidbody is inserted with said'shoulder engaging said seat. v t

V 19. In a spark plug, the combination of a body of insulating material.a central electrode secured in saidbody, a metallic shell in which saidbody is inserted and a deposit of electrically conductive material onsaid body-extending from a to the end of said electrode to a pointadjacent said shell and deposited thereon; by liquefying said material,atomizing said liquefied material and projecting saidatomized'materialon said body by a blast of gas.

20. In a spark plug, the combination of a body of insulating material, acentral elec-' trode secured therein, and a deposit of electricallyconductive material on said body, at a point adjacent the end ofsaidelectrode, deposited thereon by liquefying said material, atomizing saidliquefied material and projecting said atomized material on said body bya blast of gas.

21. The process of making spark plugs comprising the securing of acentral electrode in abody formed of insulating material and thedepositing of a sheath of electrically conductive material over the topof said'body and in contact with said electrode by liquefying saidmaterial, atomizing said liquefied material and projecting said atomizedmaterial on said body by a blast of gas.

22. The process of making spark plugs comprising the fitting of ametallic cap over the top ofabody of insulating material and securingsaid cap to said body by depositin sealing material on the adjacentsurfaces or said cap and body by liquefying said material, atomizingsaid liquefied material and projecting said atomized material on saidsurfaces by a blast of gas.

28; In a spark plug, the combination of a body of insulating material, acentral elec trode secured therein, and a terminal cap comprising acoating of electrically conductive material deposited on the top of saidbody and in contact with said electrode by liquefying said material,atomizing said llquefied material and projecting said atomized materialon said body by a blast of gas.

24. In a spark plug, the combination of a body of insulating material, ametal terminal cap fitting over the top of said body and a deposit ofsealing material on the adjacent surfaces of said cap and body depositedthereon by liquefying said material, atomiz ing said liquefied "materialand projecting said atomized material on said surfaces by a blast ofgas.

25. The process of making spark plugs comprising the positioning of abody of insulating material in a metal shell and securing said body inposition by sealing material deposited on the adjacent surfaces of saidpoint in proximity ing said atomized metal on said shoulder by a blastof gas, and inserting said .body in shell and body by liquefying saidmaterial,-

atomizing said-liquefied material and pro- .jocting said atomizedmaterial on said surfaces b a blast of ga s.

26. na spark plug, the combination of a inetal shell,' a body ofinsulating material disposed within said shell and sealing mate- 'rialdeposited on the adjacent surfaces of said shell and bodyby'liquefyingsaid material, at'o'mizing said liquefied material andprojecting said atomized material on said surfaces by a blast of gas.

27. The process ofmaking spark plugs. comprising depositing a layer ofrelatively", soft metal on, the shoulder of a body of insulatingmaterial by liquefying said metal, atomizing said liquefied metal andprojecta metal shell provided with an internal seat with said shoulderengaging said seat. 4

- 28. The process of making spark plugs comprising the forming of a bodyof insulating material. rov'ided with a shoulder, placing a layer 0gasket material on the internal 1 seat of a metal shell, fixing saidgasket mate rial-in place by depositing a layer of sealin material onthe surface of the gasket material and the. adjacent surface of themetal shell by liquefying said material, atomizing .said liquefiedmaterial and projecting said atomize'dmaterial on said surfaces by ablast of gas, and inserting said body in said shell with the shoulderengaging said; gasket material to make a as tight joint.

29. In a sparkpl g, the combination of a bodyof insulating materialprovided with a shoulder, a layer of relatively soft metal deposited onsaid shoulder by liquef ying said metal, atomizing said liquefied metaland projecting said atomized metal on said shoulder by a blast of gas,and a metal shell provided With an internal seat cooperating with saidshoulder. v

' 30. In a spark plug, the combination of a body of insulating materialprovided with a shoulder, a metal shell provided with an internal seat,a layer of gasket material disposed on said seat and a layer, ofsealingmaterial deposited onthe surface of said gasket material and theadjacent surface of said shell by liquefying said material, atomizingsaid liquefied material and projecting said atomized material'on saidsurfacesby a blast of gas, said shoulder cooperatmg with said gasket toform a gas tight joint.

31. The process of making sparkplugs comprising the coating of a portionof the In testimony whereof I afiix my'signature I in the presence oftwo witnesses. I

v CHESTER H. BRASELTON. Witnesses:

G. T. HEINz,

R. B. MUNDAY.

